Pressing and Turning

Tool Solidifies Metals and Alloys.

Exhibitor

Product description

Components or fixtures made of high-strength materials enhance the safety of buildings, plants or vehicles. Moreover, the use of extremely solid materials allows parts to be made smaller and lighter. Manufacturing such components requires the microstructure of the raw material to be influenced in a specific way in order to optimize it for high strength. In the laboratory, this is mostly achieved by High Pressure Torsion, or HPT for short, a forming technique using rotation under high pressure. However, this HPT process so far has the drawback of allowing only semifinished products roughly of mint size to be manufactured. Scientists of the KIT Institute for Nanotechnology (INT) further developed the HPT process to allow also larger semifinished products to be made. The forming tool developed at the KIT consists of a three-part thickwalled tube. A die forces raw material in from the top under high pressure. The lower part of the tool is open at the bottom end, thus allowing the molded part to be forced out. Twisting the central part of the tool relative to the fixed top and bottom sections causes a strong shear stress to act on the raw material. The inner diameter of the tool varies from top to bottom. The narrowest section, situated in the bottom part of the tool, is designed so that the pressure is sufficiently high throughout the entire tool. Pressing and simultaneous twisting cause the material to solidify. If short cylindrical metal pieces are used as a raw material, these pieces can be joined merely by high pressure and shear stress. In this way, extremely strong metal rods of any length can be manufactured which can be processed further, for instance, into structural rolling material or cold-drawn wires. Besides solid blanks it is also possible to use precompacted powders of rapid machining steel, recycled materials and chips, granulate, and strips. The KIT is looking for partners for further development and application of the method.